Rotary automatic cut-off valve



(No Model.)

H. P. HODGES.

ROTAR'YAUTOMATIO GUT-OFF VALVE. No. 330,328. Patented Nov. 10, 1885.

FIG .1.

HORACE F. HODGES, OF BOSTON, ASSIGNOR TO CHARLES F. PAYNE, OF GROVELAND, AND GEORGE H. SPENCER AND CHARLES T. CROCKER, OF

FITCHBURG, MASSACHUSETTSu ROTARY AUTOMATIC CUT-OFF VALVE.

SPECIFICATION forming part of Letters Patent No. 330,328, dated November 10, 1885.

Application filed June 28, 1884. Serial No. 136,311. (No model.)

To all whom it may concern:

Be it known that I, HORACE F. Honens, a citizen of the United States, residing at Charles,- town, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Rotary Automatic Cut-Off Valves, of which the following is a specification.

My invention relates to that class of valves 1 in which the speed of a motor is regulated by the automatic lengthening or shortening of the interval of the stroke during which the steam is admitted to the cylinder, and which is ordinarily called the cut-off.

The invention consists in a valve having a constant rotary motion and an automatically-regulated longitudinal motion the first of which admits steam at stated periods and the latter determines the period of time during which the steam is admitted, in other words, cuts off the steam earlier or later in the stroke.

In the accompanying drawings, Figure 1 is a vertical longitudinal section of a valve embodying my invention, showing its position 2 5 when steam is admitted during the whole stroke or when the engine is at rest. Fig. 2 is a similar view showing the position when steam is admitted during half the stroke and at the point at which the port is open. Fig. 3

is a vertical transverse section on the line as x of Fig. '1, showing the valve fully open. Fig. 4 is asimilar view showing the valve fully closed, and Fig. 5 is an elevation of the rotary valve.

3 5 Similar letters indicate like parts in the several figures.

A is the body or shell of the valve. A is the valve-well, and constituting the seat of the valve proper. B is atubular valve adapted to 40 rotate within the well A. The valve B is provided with two opposing ports E E, whose length circumferentially is equal to one-quarter of the outer circumference of the valve B, as indicated in Figs. 3 and 4, while the widths 5 of the said ports are made sufficient to furnish the requisite port-room inside. The ports E E are placed opposite each other, for the purpose of equalizing the efi'ect of the pressure, and also to admit of a slower rotation of the valve in consequence of the ports opening twice during each revolution. More than two ports can be employed, provided they are so arranged as to balance the pressure of the steam upon the valve and that their length equals the space between two adjacent ports. The outer surface of the valve is provided with any suitable packing, G.

D D are ports leading from the valve-well A and connecting with the steam-passages F F, and whose dimensions correspond with the ports E E in valve B. These ports must always correspond in length with those in the valve. The ports D D and E E are of diamond shape, as shown in Figs. 1 and 2; or they may be of ellipsoidal or triangular shape, as de sired. When of triangular shape, one side of the triangle should be parallel with the axis of the valve. In a diamond or ellipsoidal shaped port cut off is effected by both delaying the time of admission and hastening the time of closure, or vice versa,while with a triangular or a semi-ellipsoidal port the time of closure alone is afiected.

bis a cross-bar within the valve B, by which the said valve is attached to the spindle H, of which latter H is a portion made square or polygonal, by which means the spindle is caused to rotate when connected with an engine, and at the same time allowed a longitudinal movement.

C C represent a governor, to which the valve-stem is connected, and which is made the subject of a separate application.

The operation is as follows: Steam being admitted from the main enters the passages F, passes through the ports D D and E E, and thence to the cylinder of the engine, as indicated by the arrows in Figs. 2 and 3, thus causing the engine to revolve, and with it the valve B. As the latter revolves, the position of the ports E E changes from that shown in Fig. 3 to that shown in Fig. 4, in which latter steam is prevented from passing through the valve. It will be seen, however, that when the valve is closed it immediately commences to open the solid portions of the valve B, just equaling the length of the ports, each being ninety degrees. If, however, the valve beimoved by the action of the governor, as indicated in Fig. 2, the lengths of coincident openings of the ports D and E are reduced, as shown by their intersection at the points (1 and d, the result of whichis a longer interval between the open-'- ing and closing of the valve, this being there sult required. It is evident that the farther the valve B is pushed in the direction of the arrow by the governor, as seen in Fig. 2, the longer will be the interval of closure, or vice versa.

It is further evident that steam may pass in v and whose circumferential length is equal to the spaces between ithem, said 'valve being adapted to have a longitudinal movement, all in combination with a valve well or seat having ports of similar dimensions and arrangement, substantially as specified. I

2. The tubular valv'e'B, open from end to end and having ports E E, arranged at equal distances apart on theoircumference and of a length equal to the spaces between them, the said valve being provided with a bar, I), in

combination with the valve-spindle H and the 'B, substantially as shown and described.

:In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

V HORACE F. HODGES. 'Witnesses:

J. H. ADAMS,

PLANTA. 

